The present invention refers to a device for the electrical transmission of a mechanical variable, particularly an electric gas pedal for automotive vehicles, having a first potentiometer system as desired-value transmitter from which an electric desired-value signal can be fed to an electric control unit, and having a controlling element which can be controlled by electric signals from the controller unit,and the adjustment range of which is smaller than the adjustment range of a second potentiometer system as actual-value transmitter which is connected therewith.
Devices are already known by which the instantaneous position of the accelerator pedal is transmitted electrically to the throttle valve of the carburetor of an automotive vehicle, or the control rod of the injection pump. For this purpose, an electric position transmitter in the form of a variable resistor (potentiometer) is coupled mechanically as desired-value transmitter to the accelerator pedal. In similar manner, the position of the throttle valve or the control rod of the injection pump is indicated by a second variable resistor (actual-value transmitter). Throttle valve or control rod as fuel-measuring elements are in this case driven by an electromagnetic device and controlled by a control circuit primarily for correspondence between desired value and actual value. The electrical transmission of the position of the accelerator pedal, in addition to the simplicity of the laying of the wires thereof, has the advantage over rods or Bowden cables that the torque and power of the internal combustion engine driving the automotive vehicle can be varied electronically in various ways from a standpoint of safety. The potentiometers of the prior art which are used as desired-value and actual-value transmitters must, in general, be adjusted at the factory. Changes in the characteristic curve due to increased contact or leakage resistances as a result of dirt, moisture or corrosion must be monitored so that uncontrollable propulsion values of the automobile do not lead to dangerous driving conditions.